In the prior art, a router with a cutting depth adjustment mechanism is known. The cutting depth is usually adjusted manually by loosening a clamping device located in the support foot of the router. However, this method of cutting depth adjustment is not precise enough to be acceptable. To achieve a precise cutting depth adjustment, Bosch's U.S. Pub. No. 20070065245A1 discloses a precise cutting depth adjustment mechanism that finely adjusts the cutting depth by rotating a motor housing relative to the support foot of the router. This method is not convenient for the operator and the adjustment mechanism disclosed is complicated.